Fifteen-year-old Caleb Sharpe has been identified as the gunman who allegedly opened fire on his classmates at his high school near Spokane, Washington.

The rampage killed one student and injured three others.

The suspect was detained, according to a tweet by the Spokane County Sheriff's Office.

As investigation continues, details of the shooting and the suspect are emerging. Here's what we know about Sharpe:

Breaking Bad:

The teenager is reportedly a fan of the popular television series “Breaking Bad.”

“He was weird,” Michael Harper, who said he was a close friend of Sharpe’s, told The Spokesman-Review. “And he loved the show ‘Breaking Bad.’ He never really seemed like that person who had issues. He was always nice and funny and weird.”

In a Facebook account, believed to be Sharpe's, he can be seen on his social media posing as The Joker from the Batman series.

On a YouTube account, also believed to be Sharpe's, he can be seen showing off his gun collection and simulating shootings.

In fact, just in May, the teenager purportedly filmed a video, entitled “J-Baumb kills Mongo," showing him having a mock shooting. The videos are now offline.

Shooting Documentaries:

Another student stated Sharpe had also become obsessed with school shooting videos.

"I was thinking that maybe it wasn't my friend but then I had an idea it was all the documentaries he's been watching and thinking he sent me a picture on Snapchat when we were talking and it was a documentary and I was like: 'There's no way he could do this!' Now I'm thinking he might actually have gone through with it."

Hints:

According to some Freeman students, Sharpe dropped some hints about the shooting "a few weeks ago."

"He was handing out a note to his friend saying he would do something stupid that could get him killed or in jail," one student told KXLY television.

Details of the shooting from law enforcement have yet to emerge. However, Spokane County Sheriff Ozzie Knezovich told reporters: “It sounds like a case of a bullying-type of situation.”

Sharpe is currently being held at the Spokane County Juvenile Detention Center.